ANÁLISIS DEL TRANSPORTE DE OZONO EN LA CUENCA ATMOSFÉRICA DE PUEBLA-TLAXCALA EN EL CENTRO DE MÉXICO

A study on the dynamic of transport and occurrence of ozone in the air basin of the Puebla-Tlaxcala Valley (PTV) was performed between March and April 2012. The ozone (O 3 ), nitrogen oxides (NOx) and several meteorological variables were measured at the surface level in the rural sites of Huaquechula (HUAQ), Chipilo (CHIP), and Amozoc (AMOZ). The vertical O 3 profile and the associated meteorological conditions, were measured intermittently in CHIP. The 1 hour Mexican air quality standard of 0.095 ppm for O 3 , was exceeded in five and one days in CHIP and AMOZ, respectively. A rapid increase in the morning for O 3 levels was observed in the three sites and was associated with the mixing of O 3 above the inversion layer once started the growing of the turbulent mixing layer. Unusual O 3 evening events of around 0.080 ppm were recorded for several hours in the three sites that could be associated with the recirculation of air masses with ozone formed within the VPT and O 3 advectively transported from the Cuernavaca-Cuautla Valley. The vertical O 3 profile showed an increase with height at concentrations even higher than those observed at the surface, and the 2-D analysis of backward trajectories suggested favorable conditions for O 3 transported from the free troposphere to the surface. It is concluded that the implementation of control strategies in the VPT should consider the influence of the inter-basin exchange, the meteorological local and synoptic seasonality, and the possible contributions of O 3 from the free troposphere and not be limited to local conditions.